First Fifty Theses

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Three contributions to the theory of recursively enumerable classes.

Peer reviewed: 
No, item is not peer reviewed.
Date created: 
1967
Abstract: 

Priority arguments are applied to three problems in the theory of rce. classes. Chapter I: A conjecture of P. R. Young in A Theorem on Recursively Enumerable Classes and Splinters, PAMS 17,5 (1966), pp. 1050-1056, that an r.e. class can be constructed with any pre-assigned finite number of infinite r.e. subclasses, is answered in the affirmative. Chapter II: Standard classes and indexable classes were introduced by A. H. Lachlan (cf. On the Indexing of Classes of Recursively Enumerable Sets, JSL 31 (1966-),, pp. 10-22). A class C- of r.e. sets is called sequence enumerable if the r.e. (3- is indexable => fl. is subclass enumerable, but none of the implications can be reversed. Chapter. Ill: A partially ordered set (&,<} is represented by the r.e. class G- if (&,<} is isomorphic to (C-,E). Sufficiently many p.o. sets are proved representable to verify a conjecture of A. H. Lachlan that representable p.o. sets and arbitrary p.o. sets are indistinguishable by elementary sentences.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Name is illegible
Department: 
Science: Mathematics Department
Thesis type: 
(Dissertation) Ph.D.

Photolyses of N-nitrosamides in acidic and neutral media.

Peer reviewed: 
No, item is not peer reviewed.
Date created: 
1967
Abstract: 

Photolyses of several N-nitrosamides in acidic and neutral media were studied. The photochemical decomposition of II-nitrosanides was found to involve exclusively nitrogen-nitrogen bond cleavage of the IT-nitrosamide group in contrast to the pyrolytic decomposition which involved cleavage of the acyl nitrogen bond. In acidic media, photolyses of rl-nitrosamides led to the light catalyzed denitrosation of the N-nitrosamides by photo-elimination of the [WOH] group with the formation of alkylidenimides. The alkylidenimides underwent secondary reactions to give the corresponding aldehydes. The photo-elimination products were identified as the 2 ,4-dinitrophenyl-hydrazones of the aldehydes. In neutral media, the primary photolytic process of H-nitrosa.nides was the .formation of nitroso and amide radicals. The amide radical v/as found to abstract intramolecularly a $ hydrogen atom attached to the carbon atom in the S-position^ to give a S-carbon radical. This S-carbon radical then coupled with the nitroso radical to give a C-nitroso compound which either tautomerized to form oxime or dimerized. Alternatively the amide radical underwent elimination of an alpha hydrogen to give the alkylidenimide as an intermediate. if The S-position was numbered in reference to the nitrogen atom of the amide group. For examole , the for vula of & -nitroso-n-hexylformamide would be N=0 0 Ill

Document type: 
Thesis
File(s): 
Senior supervisor: 
Name is illegible
Department: 
Science: Chemistry Department
Thesis type: 
(Thesis) M.Sc.

Epistemology, cybernetics and uncertainty : philosophical observations on the work of Warren McCulloch and John Dewey

Author: 
Peer reviewed: 
No, item is not peer reviewed.
Date created: 
1968
Abstract: 

This thesis considers the application of information theory concepts to the problems of epistemology. It attempts to demonstrate that such formalistic concepts by nature must neglect the fundamentally behavioral aspects of thinking, Part I attempts to describe a predicament which is widely felt today, that of man's inability to control a world of his own making. It is then proposed that a comprehensive theory of human behavior is what is required to deal with the predicament. Part II compares the theory of "Experimental Epistemology" of Warren 5. McCulloch with the theory of "Inquiry" of John Dewey. Basically McCulloch's equation of sense data with information and his acceptance of negative feedback as explanatory of purposeful behavior is attacked. Further his assumption of Cartesian Dualism and attempts to resolve it through reductionism are considered in detail. Dewey's theory of "Inquiry" is proposed as a suitable alternative to explain how we gain warrantable assertibility as the foundation for our judgments of practice. His rejection IV of any general theory of reality and insistence upon the social cultural and behavioral aspects of thinking are noted. Part III considers the educational implications of both theories, by analyzing the kinds of choice they deal with and the consequent kinds of control they proffer. Educiational ends are proposed which recognize the human organism as a dynamic process, and requirements for means to such ends are stipulated

Document type: 
Thesis
File(s): 
Senior supervisor: 
Frederick J. Brown
Department: 
Education: Behavioral Science Foundations
Thesis type: 
(Thesis) M.Ed.

A visual-motor test and a perceptual-reasoning test as discriminators of academic achievement.

Peer reviewed: 
No, item is not peer reviewed.
Date created: 
1968
Abstract: 

This study was designed to explore Che effects of visual perceptual abilities as determinants of school achievement and to provide some information about two tests in this area. Other aspects of achievement were also examined. The Bender Gestalt Test and the Raven Progressive Matrices (1947) were administered to two hundred and fifty-six children in kindergarten, grade one and grade two. One hundred and twenty-two children were classified as low achievers and one hundred and thirty-four as average achievers. .The effects of achievement level, grade level, age within grade, and sex, upon the children's visual perceptual performance scores were studied. The two achievement groups were examined to note similarities or differences in the children's date of birth, age within grade and sex. The results indicate that both the Bender Gestalt Test and the Raven Progressive Matrices discriminate significantly between children in the three grade levels and between children in the two achievement levels. Neither test significantly discriminated between male,and female or between young and old within the grades. Birthdate (May to August) did not relate significantly to achievement. Birthdate (September to January) did relate significantly to achievement as did age within grade. The sex of the children was also found to be significantly related to achievement' level. These results were discussed and implications for further research in the area of predictive visual perceptual screening devices were advanced. Implications for the study of the effects of sex, birthdate and age within grade on school achievement were also discussed.

Document type: 
Thesis
File(s): 
Senior supervisor: 
R.J.C. Harper
Department: 
Education: Behavioral Sciences
Thesis type: 
(Thesis) M.Ed.

Observations on the growth and physiology of Pinus strobus L. seedlings grown under various conditions of soil moisture and nitrogen and phosphorus nutrition.

Peer reviewed: 
No, item is not peer reviewed.
Date created: 
1967
Abstract: 

PART I White pine seedlings (Pinus strobus L.) were grown at high or low soil-moisture levels. The leader stem length, fresh weight of the seedlings, respiration, photosynthesis, transpiration, translocation of photosynthate from shoots to roots, and bio-electric potentials between the tip and the base of the stem were measured throughout the growing season from April to October. At both moisture levels the lowest translocation of recent photosynthate from shoots to roots occurred during early summer, or at the time when the rate of root growth was the lowest and that of the shoot the highest. During 14 early summer the specific activity of CC>2 respired by the shoots of such plants remained high throughout an 8 h experimental period, indicating a continuous utilization of recent photosynthate as a respiratory substrate. On the other hand, early and late in the growing season, when translocation of recent photosynthate from shoots to roots and the rate of root growth were high, the specific activity 14 of CO- respired by the shoots rapidly decreased during the ^ 8 h experimental period, indicating a drop in the utilization of recent photosynthate as respiratory substrate. The highest positive values for the potential difference between the top and the base of the main shoot also occurred in early summer or during the period of high rates of i canspiration. PART II Potted white pine (Pinus strobus L.) seedlings were grown on media containing different amounts of nitrogen (N) and phosphorus (P). The seedlings were grown either in controlled environment chambers or outdoor cold frames. Following periods of five, seven and thirteen weeks on treatment the seedlings were analyzed to determine rates of respiration, photosynthesis and the degree of translocation of recent photosynthate to the roots. Shoot and root fresh weights were recorded. Analyses were made to determine the metabolic fate of the translocated sugars. The best overall growth and the highest root/shoot ratios were found in seedlings receiving intermediate levels of N and P. The range of nutritional conditions employed was found to have no effect upon rates of shoot and root respiration or photosynthesis, even after thirteen weeks of treatment. Lateral root formation was depressed under conditions of high N and P. Mycorrhizal abundance showed a maximum at intermediate levels of nutrients. Translocation of recent photosynthate to the roots was depressed by high P, this depression was however, reversed to some extent by increasing N levels. The hydrolysis of sucrose recently translocated to the roots was increased with increasing N supply. The resultant hexoses being metabolised to amino and organic acids. However, sucrose continued to be the dominant form in which VI 14 recently translocated C occurred in the roots. High levels of P reduced the effect of N on the metabolism of translocated sucrose. Relatively very few of the metabolically active compounds, isolated from the soluble fraction of the roots, showed distinct patterns of change which could be correlated to either the different nutritional levels of N and P supplied or to the incidence of mycorrhizae.

Document type: 
Thesis
File(s): 
Senior supervisor: 
C.D. Nelson
Department: 
Science: Biological Sciences
Thesis type: 
(Dissertation) Ph.D.

Recombination kinetics in CdS.

Peer reviewed: 
No, item is not peer reviewed.
Date created: 
1967
Abstract: 

In high-purity cadmium sulfide crystals,, at low temperatures and high excitation intensities, emission lines attributed to free and bound exciton recombination are observed in the spectral range 4860 to 5090 A. In addition, the main peaks of two broad emission bands, which are repeated at lower energies with the simultaneous emission of one or more longitudinal optical phonons, are observed at about 51^-0 and 5180 A.. The high energy band, which is d.ominant at liquid, nitrogen temperatures, is d.ue to free electrons recombining with holes bound at cadmium vacancy acceptors. The low energy band, which is dominant at liquid helium temperatures, is due to electrons bound to shallow donors recombining with the bound holes. The photoluminescence efficiency and photoconductivity response of cadmium sulfide crystals were measured and the data interpreted in terms of an energy band model involving the donor and acceptor levels previously established as being involved in the radiative transitions. In addition, an effective recombination center (consisting of deep acceptor-like recombination centers) and non-radiative surface recombination centers are required to account for the non-radiative transitions. The results of the thesis are divided into four topics and are summarized below. The first topic deals with the controversy in the literature regarding the origin of the high energy emission band at about 51^-0 A. Two recent papers, which identify this band, as being due to bound electron-to-bound hole transitions, are analyzed and. it is shown that their conclusions are incorrect. Further ii, analysis and experiments show that their data support the free electron-to-bound electron interpretation of other authors. The second topic was the effect of surface recombination centers on the luminescence efficiency. These states are believed to be mainly chemisorbed oxygen ions. Non-radiative surface recombination is reduced by applying an electric field to counteract the electric field in the charge depletion layer next to the surface, or by phot o-d.es orb ing the oxygen ions. This electric field d.raws minority carriers to the surface where they recombine non-radiatively. The luminescence efficiency is found to be lowest when the electron-hole pairs are generated.,, closest to the surface. This is interpreted as meaning that a greater fraction of the carriers can reach the surface to recombine and that ambipolar diffusion of carriers into the interior of the crystal does not take place. It was also found, that heating CdS briefly in a nitrogen ambient produces free-to-bound and bound-to-bound transitions associated with nitrogen acceptors 130 meV above the valence band. The nitrogen impurities are near the surface since these band.s are removed by a short etch in concentrated hyd.rochloric acid. The third topic was the recombination kinetics of excitons and the bound, electron-to-bound hole luminescence. In all cases, the exciton efficiency increases with increasing excitation intensity as expected since the formation of excitons depends on the prod.uct of the free carrier densities. The bound-to-bound emission efficiency is high and varies slowly with excitation intensity. The efficiency falls slowly both at high and at ill. low excitation intensity. The fall-off in efficiency at high excitation intensity is accompanied by an increase in efficiency of the free-to-bound emission band. The decrease in efficiency at low excitation intensities may be due to non-radiative surface recombination. The last topic was the recombination kinetics of the free electron-to-bound hole luminescence. Using the energy band model mentioned earlier, the data was analyzed to obtain the electron and hole lifetimes, the luminescence efficiency, and the electron and hole capture cross-sections of the cadmium vacancy acceptor and the other d.eep recombination center. The internal luminescence efficiency is near unity as long as the minority carriers (holes) are quickly captured by the radiative recombination centers (cadmium vacancies). At high temperature the luminescence efficiency is low because the cadmium vacancy centers act as traps rather than recombination centers, while at high excitation intensities the efficiency drops because the radiative transitions saturate.

Document type: 
Thesis
File(s): 
Senior supervisor: 
K. Colbow
Department: 
Science: Physics Department
Thesis type: 
(Dissertation) Ph.D.

The controversy surrounding the Davis-Moore explanation of stratification.

Peer reviewed: 
No, item is not peer reviewed.
Date created: 
1968
Abstract: 

We attempt to apply Mannheim's discussion of the sociology of knowledge to the controversy surrounding the Davis-Moore argument. Mannheim distinguishes between the immanent and extrinsic interpretation of a body of intellectual knowledge, that is, between,on the one hand,interpretation in terms of the premises prescribed by an intellectual work, and on the other, while holding the basic premises in abeyance, in terms of its relationship to the wider existential situation. Extrinsic explanations seek to relate the thinker's political "perspective" to his position in the wide^ social system, mainly in terms of the "class" or social group, to which he belongs. For example, Mannheim interprets nineteenth century German conservative thought as a response, generated by the needs of the class to which its creators belonged, (the "declining bourgeois class") to the challenge to its position by another class ("the ascendant group.") We claim that, to a large degree, the controversy is explicable in terms of the conflict of political perspectives on the problem of social inequality, with the qualification that one area of the exchange is basically a conflict of methodological axioms which does not rmnlfest an underlying clash of political opinions. Perspectives are identified by the exaggeration of some facts about human societies, as generally conceived, to the exclusion of others; and, by the failure of proponents and critics alike to consider relevant empirical evidence and theoretical arguments presented by other thinkers. We claim that proponents adopt a conservative, their critics a liberal view of stratified inequalities. Further, when the perspectives of different contributors are viewed as representative of wider trends of the political thought of American intellectuals throughout the twentieth century, a new dimension of meaning is afforded the controversy. Thus, the implicitly conservative argument presented by Davis and Moore is viewed as part of the post-war conservative reaction to the radicalism of American liberal intellectuals during the early thirtie.s and to their committment after 1936, to N=w Deal measures to reduce the scale of prevailing social and economic inequalities. Criticisms of their argument are viewed as a liberal counter-attack, prompted by the intellectual articulation of conservative thought in the early fifties, and which reflect, in their essentially limited and defensive approach, the climate of opinion of American liberal intellectuals in the post-war period. Whilst many of Mannheim's statements are supported by our discussion, especially those concerning the development of conservative thought as a "counter-ideology," to meet the challenge of another alien and hostile ideology, his statement that the perspective of an intellectual work is determined by the needs and aspirations of the class or group to which its creator belongs, rraast be modified on the basis of our examination of major trends of intellectual thought in American society; The major developments in American political theory were not generated by the needs or aspirations of well-defined social groups, but by such variables as the changing conditions of the American economy, for example, the Great Depression, the New Deal reforms and the later recovery of the capitalist economy both at home and abroad during the post-war period; the prevailing mood of the American public as expressed in post-war conservatism; and, America's relationship to the rest of the world, particularly, the emergence of a polar confrontation between America and Russia.

Document type: 
Thesis
File(s): 
Senior supervisor: 
David C. Bettison
Department: 
Arts and Social Sciences: Department of Political Science, Sociology and Anthropology
Thesis type: 
(Thesis) M.A.

The formation and decay of the compound mucleur Ge 68.

Peer reviewed: 
No, item is not peer reviewed.
Date created: 
1968
Abstract: 

Experimental excitation functions have been measured by radiochemical means for a number of reactions proceeding through the compound nucleus Ge . The target- li 54 TO ^f, 16 52 projectile pairs were: He +Zn , C +Fe , and 0 +Cr leading to the following reactions: (OO,Y), (x,p), (x,n), (x,pn), and (x,2n). Recoil ranges were measured for products of the alpha-induced reactions in order to determine those reactions which proceeded by compound nucleus formation and decay. It has been found that the "independence hypothesis" is verified for reactions induced by different target-projectile pairs but proceeding through compound nuclei of nearly equal angular momentum. Excitation functions have been calculated with the SFU IBM System. ^60/40 computer via the statistical theory of nuclear reactions according to a formalism containing the explicit dependence of nuclear emission probabilities on angular momentum. Probabilities for Y-ray emission were calculated according to the single-particle model coupled with enhancement functions chosen to reflect experimentally observed collective effects. Agreement between experiment and calculations 64 4 was found to be good for the Zn +He excitation functions. The "high energy tails" of the excitation functions were found to be accounted for by effects of y-ray competition with particle emission when the latter was surpressed by angular momentum effects. Agreement in the Fe +C case was found to be very encouraging, considering the complexity of the target-projectile system and attendant theoretical difficulties.

Document type: 
Thesis
File(s): 
Senior supervisor: 
B.D. Pate
Department: 
Science: Chemistry Department
Thesis type: 
(Dissertation) Ph.D.

The poetry of Raymond Souster.

Author: 
Peer reviewed: 
No, item is not peer reviewed.
Date created: 
1968
Abstract: 

Despite Raymond Souster's acknowledged stature as major Canadian poet, no in-depth study of his poetry has been made. Consequently, basic misconceptions exist, the most fundamental one being the tendency to consider Souster's poetry as being static. This thesis is intended to fill partially the void of criticism, thereby erasing the above misconception. The Introduction contains a brief biographical note and description of the literary climate existing when Souster began writing, Chapter II traces the development of Souster's poetic style and examines the influences upon his poetry. Through time, these influences have been the poetry of Kenneth Fearing, Kenneth Patchen, Ezra Pound, William Carlos Williams, Charles Olson, and Robert Creeley. The third chapter deals with the full range of Souster's poetry, discussing the interplay of both fear and joy operative in Souster's treatment of the city, nature, woman, and youth. Munro Beattie, for instance, in his Literary History Of Canada (p. 780), states that the form of Souster's poetry has changed scarcely at all since 19^3? Desmond Pacey in Creative Writing in Canada (p. 1?*0 , asserts that although the poems have not deteriorated, there has been no significant development in Souster's poetry since the early 19*4-0's.

Document type: 
Thesis
File(s): 
Senior supervisor: 
L. Kearns
Department: 
Arts and Social Sciences: English Department
Thesis type: 
(Thesis) M.A.

An approach to the study of the physiological control of translocation in higher plants.

Peer reviewed: 
No, item is not peer reviewed.
Date created: 
1967
Abstract: 

Tne elective or tnis -nvestiga^icn v/a^ to ?'-,?ai.'. __.e insight into wnat limits or cor.trc^ transl^catior. i:" hi /. ~ plants. ?/ Photosynthesis and trans location xv^r^ studied v..,_.'.-v ^""CO.-,. Over 75% of the assimilated ~ c W?s incorporated into surcro~e via aspartic acid and malic acid. About 20% cf the "^C v.vnt _..tc ethanoi-insoluble compounds. Lowering the temperature to o" '?? ?delayed the incorporation of the ^ ""C i^to sucrose, out hac. little effect on the rate or amount of incorporation. In young corn plants all the leaves exported C, most of which went to the roots and the growing regions of the plants. Ail the leaves imported some 14G assimilated in other leaves. The only translocated organic compound in corn was sucrose-It was translocated down the leaf blade at a velocity in excess of 150 cm hour . The transiocation profile in the leaf blade v/as logarithmic and was found to be due to a reversible accumulation of t;.e translocate in the vascular tissue. Corn leaves were used to establish a method for measuring 14 transiocation from the leaf. Measuring the amount of C remaining in the fed area of leaf at various times after feeding ""^2 provided information on 3 characteristics of translocaticn; the relative rate of transiocation from the leaf, the total percentage of the assimilated C that is translocated, and the turnover time of the transiocation pool. From these measurements the transioca- tion in corn at 2600 ft-c was calculated to be 327 ugm of sucrose -2 -i d.;. mm . The turnover time of the transiocation pool in corn v,-_s 80 minutes. This method was used to study the effect of different factors on transiocation from the leaf. A decrease in te:..oari.tu.^ decreased the rate of translocation more or less linearly from 26 to 7? The turnover time of the translocation pool and the percentage of the assimilates translocated increased with a decrease in temperature. Light had no significant effect on translocation. The rate of translocation and the percentage of the assimilates translocated changed with the age of the leaf. The method of measuring the C remaining in the fed area of leaves was used in a comparative study of translocation in a number of species. The relative rate of translocation and the percentage of the assimilates translocated varied with the species. Corn, sorghum, millet and sunflower translocated between 70 and 90% of the assimilated ^C in 24 hours, whereas the other species translocated only between 40 and 60%. The compounds in which the 14C was held back in the leaf varied with the species. The turnover time of the translocation pool divided the species into 2 groups; tomato and radish had a turnover time of 40 minutes, all the other species had a turnover time of about 80 minutes. The result of the investigations suggest that the limiting process in translocation is the transfer of the translocate from the assimilating cells to the phloem. It is speculated that the main part of the control of translocation is at the membranes of the exporting cells.

Document type: 
Thesis
File(s): 
Senior supervisor: 
C.D. Nelson
Department: 
Science: Biological Sciences Department
Thesis type: 
(Dissertation) Ph.D.